• CHINESEBOTTROLL@sh.itjust.works
    link
    fedilink
    arrow-up
    2
    ·
    edit-2
    1 jaar geleden

    I guess it depends on the place. But the arguments for not including seem futile, when

    • we use 0 to even write the other natural numbers
    • we define almost all of our algebraic objects (groups, rings/fields, modules/vector spaces, algebras) to include 0
    • we don’t do modular arithmetic with {1,…,n} that would be crazy

    Of course 0 vs no 0 only matters if you actually do arithmetic with it. If you only index you could just as well start with 5.

    (The only reasons I can think of to start at 1 is that 1 is the 1-st element then and the sequence (1/n) is defined for all natural n)

    • Lakso@ttrpg.network
      link
      fedilink
      arrow-up
      1
      ·
      edit-2
      1 jaar geleden

      Those are valid points and make some practical sense, but I’ve talked too much with mathematicians about this so let me give you another point of view.

      First of all, we do modular arithmetic with integers, not natural numbers, same with all those objects you listed.

      On the first point, we are not talking about 0 as a digit but as a number. The main argument against 0 being in N is more a philosophical one. What are we looking at when we study N? What is this set? “The integers starting from 0” seems a bit of a weird definition. Historically, the natural numbers always were the counting numbers, and that doesn’t include 0 because you can’t have 0 apples, so when we talk about N we’re talking about the counting numbers. That’s just the consensus where I’m from, if it’s more practical to include 0 in whatever you are doing, you use N0. Also the axiomatization of N is more natural that way IMO.

      • CHINESEBOTTROLL@sh.itjust.works
        link
        fedilink
        arrow-up
        3
        ·
        1 jaar geleden

        I’ve talked too much with mathematicians

        You are talking to one right now :) (not sure if a bachelors degree is enough to call yourself one)

        you can’t have 0 apples

        You can actually. In fact, right at this moment I have 0 apples. If 0 is not natural, then you have no way of describing the number of apples I have.

        There are a lot of concepts (degree of a polynomial, dimension of a space, cardinality of a set, in a graph) where 0 is a natural possibility.

        So I think 1 indexing is fine, I use it all the time, but to me 0 belongs with the natutals. I will say tho, that 0 does not make sense to me as an ordinal. “He finished the race in 0-th place”???